Spikes is coming off of his first season where he played in all 16 games, finishing with 86 tackles and an interception. During his four years in New England, Spikes had 286 combined tackles, one sack and five forced fumbles, all of which came in 2012.

The move makes a ton of sense for the Bills, as they struggled defending the run. In 2013, they gave up 128.9 rushing yards per game, ranking 28th in the league. Spikes is known best for being able to plug up rushing lanes, as Pro Football Focus (subscription required) had him as the top-graded inside linebacker in run defense and sixth-best overall.

Spikes will likely be lining up alongside Kiko Alonso in the middle of the defense in 2014, giving the Bills one of the better inside linebacker duos in the league. Alonso had a breakout rookie year in 2013, grabbing 159 combined tackles, four interceptions, two sacks and one forced fumble.

The Bills have made sure to continue to add key players to the middle of the defense, as they also brought in former New York Giants linebacker Keith Rivers. According to ESPN's James Walker, Rivers' deal is for two years and is worth $5 million:

Filed to ESPN: Free-agent LB Keith Rivers has agreed to a two-year, $5 million contract with the Buffalo #Bills.